Do you feel like your “FULL switch” is broken? Or, that you never feel quite full enough or for long enough? It might help to know that your appetite is controlled by more than just willpower. Two major hormones govern your appetite and determine how full or hungry you feel. In addition, there are two systems in your brain that affect whether you are eating for sustenance or to satisfy cravings. This means the time for blaming yourself for cravings is over! Understanding the science behind weight loss can allow you to have a healthy, happy relationship with yourself and look at weight loss in a realistic and positive way.
How appetite is controlled by systems in the brain
There are two systems in your brain that affect food intake. One of them helps turn on and off your “appetite switch”, while the other drives you to eat based on liking or wanting.
Genuine hunger – The hypothalamus homeostatic system
The Hypothalamus homeostatic system regulates appetite. It can either reduce appetite or cause you to feel “body hunger” to get your body eating necessary nutrients. Hormones in the gut, blood sugar, and fat tissues also help determine body hunger. So how can you manage body hunger? Try to eat regularly with balanced meals, and limit your intake of foods that are high in sugar and fats.
Reward hunger – The mesolimbic reward system
Have you ever felt compelled to eat even when you aren’t physically hungry? The Mesolimbic Reward system is the reason why you have these feelings. This kind of eating is often tied to stress or emotions and is the brain’s way of coping. The good news is that you can effectively manage your reward hunger by identifying food triggers. Knowing what need your body is trying to satisfy will allow you to take charge of your relationship with food. And when you understand that cravings are not your fault, but rather a result of normal biology, self-acceptance increases and self-blame washes away. This is a wonderful feeling!
Ghrelin: An important hormone in appetite regulation
When Ghrelin levels are high, it stimulates your appetite and increases your food intake. So if you were placing blame on yourself for feeling hunger even after eating, rest easy. Ghrelin is produced by your stomach and stimulates appetite (Kirchner, Heppner, & Tschöp, 2012). It causes you to feel hungry (Kirchner, Heppner, & Tschöp, 2012) and leads to an increase in body fat and weight gain (Kirchner, Heppner, & Tschöp, 2012). It is entirely possible that high Ghrelin levels are leaving you with an inability to feel full.
Leptin is the hormone that helps decrease food intake. (Kirchner, Heppner, & Tschöp, 2012). It tells your body that enough energy has been stored in fat and no more eating is necessary; as a result your body feels full and your appetite is reduced (Klok, Jakobsdottir, & Drent, 2007). Leptin also helps to stop food cravings and decrease reward (Volkow, Wang, & Baier, 2011). So why is it that obesity happens, if we have leptin to help our bodies tell us when we are full? The answer is that in obesity, due to overeating, too much leptin is produced; when too much leptin is circulating, our bodies stop reacting to it, and thus can’t get the message that it’s time to put down the fork and knife (Klok, Jakobsdottir, & Drent, 2007). If this is happening to you, you will have a much more difficult time feeling full. If you have been struggling with regular cravings, do not place the blame on yourself! These hormones exist in all of our bodies, and leave us with powerful urges that aren’t always easy to overcome.
Science affects how you manage your appetite
Understanding the hormones and brain systems that affect appetite puts you in the driver’s seat when it comes to diet. Knowing how your body works helps to remove the negative emotions that you may have about cravings – you can feel better knowing that this is not just about willpower.